Japanese Cultural Grand Prix Excellence Award / Excellent Award

"Kumiko bearing wall"
Tosa Kumiko Co., Ltd.

By Emotion

"Kumiko" is a traditional Japanese technique that expresses a beautiful geometric pattern by combining finely divided wood with grooves, holes, and hozo processing, and combining fine parts without using nails at all. It is a woodworking technique. It is said to have its roots in the Asuka period about 1400 years ago, and was used for the "banma" and "shoji" of wooden architecture, and has been inherited in the long history of Japanese culture.

And now, "Kumiko", which has been developed in each region of Japan, has been handed down as the highest technology in which joinery craftsmen compete for their skills. Against this background, Tosa Kumiko was founded in 2016 with the intention of "creating and transmitting" Tosa Kumiko "on its own."

Kumiko Tosa's founding spirit

Daisuke Iwamoto, who founded Tosa Kumiko at the age of 30 , said, "We will always challenge new manufacturing while using traditional Japanese Kumiko techniques, and innovate Japanese culture that does not fit into the frame. I am aiming for it. " Mr. Iwamoto said he wanted to work in other fields than the joinery shop of the family business. When he takes over, he finds that there are many unknown expressions in the woodworking technique that he thought was already exhausted.

Daisuke Iwamoto

It was a feeling that Mr. Iwamoto's grandfather passed down to his father to continue producing "Kumiko", which is said to be the most difficult of all fitting techniques. His father learned the technique at Kumiko's school in Saitama prefecture. Mr. Iwamoto, who trained for 5 years at his parents' house, thought about going to the same school as his father, but the only school in Japan where he could learn Kumiko technique was closed. It was.

Finally, I decided to study under the Kumiko craftsman in Miyagi prefecture, who was the same as his father, and learned the basics of Kumiko there. His monthly salary was 5 10,000 yen, and he couldn't afford to pay the rent, but he recalls, "I was taught more than that."

In 2011, he returned to Kochi after the Great East Japan Earthquake. Mr. Iwamoto said that he had learned everything that his master taught him. After that, he continued to explore the possibilities of Kumiko while working on fittings, which is his family business. Then, in 2016 , we will establish "Tosa Kumiko Co., Ltd.".

Why did you start a new company separately from his original business? Mr. Iwamoto is

To express the new possibilities of "Kumiko" and pass it on to the future.

It is said that it is the spirit at the time of establishment.

Therefore, Tosa Kumiko has produced new products such as household goods that incorporate Kumiko as well as fittings from the time of its founding, and exhibited them at the exhibition. We listen to the voices of our customers and send them out ourselves. In the regional revitalization project that was held 2 times this year at Matsuya, a department store in Ginza, Tokyo, Kumiko decorated the show window and expressed the world view of Kumiko that has never been seen before. We received inquiries from various fields, including the construction industry, and it is said that the response from women in particular was greater than expected.

Card case "Asanoha" incorporating kumiko

"Kumiko bearing wall" that no one has realized

Immediately after the company was founded, it was the production of the "Kumiko bearing wall" that was consulted. We have made a kumiko bearing wall and tested it, and are currently developing it to make it even easier to use for its widespread use. Mr. Iwamoto told me the reason why there was no bearing wall using kumiko so far.

In addition to the fundamental technical factor of making a kumiko bearing wall, "I have no idea to use a kumiko that is delicate and thin and is likely to break as a bearing wall. I think there was a stereotype in the industry that even if it were realized, there would be no demand.

In the process of manufacturing the Kumiko bearing wall, we start by selecting hinoki cypress in Kochi prefecture. Measure the moisture content of each piece of wood and use only the wood that has passed. In addition, we are still conducting product performance tests several times a year so that we can use it as a bearing wall with peace of mind. Mr. Iwamoto says, "We are currently working on expressing the performance of the Kumiko bearing wall with proper numerical values ​​so that more people can use it, so I hope you can look forward to it one year from now." ..

Kumiko bearing wall

(Co-development Holtzstra Co., Ltd.)

The reason why there are many inquiries about Kumiko bearing walls is, of course, that they are bearing walls, but I think that you may be attracted to the dignified appearance and the beautiful pattern of eight-eyed knitting as shown in the photo. .. Kumiko bearing walls, which have the strength to withstand earthquakes, have excellent daylighting and ventilation, and are beautiful in appearance, were often inquired as a renovation of traditional buildings and wooden houses at the beginning of sales, but now they are commercial facilities and individuals. It is expanding to the use of various building properties such as houses.

Inquisitive mind-in search of unseen scenery

The production of the Kumiko bearing wall was not brought to Tosa Kumiko from the beginning, but was undertaken by Tosa Kumiko while the joinery shop in Kochi Prefecture refused to do so. Mr. Iwamoto is

When people say "I can't do it anyway", they are motivated to produce and develop.

Various things can be seen in the process of clearing difficult things,

I think the road to achieving

is meaningful.

Talk to


Even if it seems difficult at first glance, the scenery that you haven't seen yet spreads over the place.

It takes an inquisitive mind to work with people who have high demands. We also incorporate knowledge from different fields. By doing so, by realizing what no one is doing, a wide variety of "drawers" will increase. This is a stack.

Kumiko bearing wall structure

(Co-development Holtzstra Co., Ltd.)

Possibility of Kumiko to connect to the future

Kumiko load-bearing wall is rare in the industry, and it is a fitting that end users directly inquire about using it. Specifications such as board), surface lattice, and lattice lattice were common. Under such circumstances, Tosa Kumiko's Kumiko bearing wall changed the structure of the construction industry and our living environment, creating a new culture. While inheriting traditional Japanese culture, there is a message for the next generation.

* "Representation" ... An architectural term that refers to finishing wood in a state that can be seen from the outside with interior, exterior, and structural materials of architecture

Mr. Iwamoto, who is currently 35 , says, "I want to retire from the line at 50 and support the younger generation." In order to make young craftsmen want to do "Tosa Kumiko" instead of "Kumiko", the spirit of "Is it new?", "Who makes me happy", "Is it fun for myself?" Based on this, I would like to pass on Kumiko technology and connect Japanese culture and Japanese beauty to the future with tradition and innovation.

Award-winning work

Title: "Kumiko bearing wall"

Dimensions: Various

Material: Japanese cypress (produced in Kochi prefecture)

Technique: Kumiko

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